I build an app which is used for meassuring outside environments on a larger scale (image the size of a regular personal driveway) using AR. In order to increase the reliability of the system I want to implement a loop closing algorithm that allows the user to set a fixpoint (e.g. ImageMarker) --> walk around --> return to the fixpoint. The system should then figure out the offset (drift) between the original marker position and the new position upon returning and apply the transformation on the measuring-points in such a way that it accounts for drift.

As far as I know this kind of system is called a "loop closure". Where do I start with implementing such a thing in ARFoundation? Are there build in methods? What are keywords / names of specific algortihms that I could be researching?

Any help is greatly appreciated. Thank you!

I experimented with two things:

• adding a simple standalone imagetrigger to the scene and check if that already has an impact on other ARAnchors in the scene -> this doesnt seem to be the case. The transformations on the other anchors do not seem to be affected when the imagetrigger updates its position.

• attaching all points of meassurment as children of the imagetrigger --> this obviously applys the updated image-trigger transformation uniformly onto all other points. However drift is not accumilating uniformly over the runtime of the system.